The characterizing group (—COOH) of certain organic acids; e.g., HCOOH (formic acid), CH3COOH (acetic acid), CH3CH(NH2)COOH (alanine), etc. Cf.:carboxylic acid.
* * *
car·box·yl kär-'bäk-səl n a monovalent group -COOH typical of organic acids called also carboxyl group
car·box·yl·ic .kär-(.)bäk-'sil-ik adj
* * *
car·box·yl (kahr-bokґsəl) the monovalent radical,
COOH, occurring in those organic acids termed carboxylic acids.
Medical dictionary. 2011.